Transmitted Drug Resistance among HIV-1 Drug-Naïve Patients in Greece.

Objectives: Despite the success of antiretroviral treatment (ART), the persisting transmitted drug resistance (TDR) and HIV genetic heterogeneity affect the efficacy of treatment. This study explored the prevalence of TDR among ART-naive HIV patients in Greece during the period 2016-2019. Methods: Genotypic resistance testing was available for 438 ART-naive HIV patients. Multivariable Poisson regression models were fitted. Results: The majority of patients were male, and there was a slight predominance of Hellenic (26.5%) over non-Hellenic (21.9%) nationality. The prevalence of TDR was 7.8%. There was a predominance of mutations for non-nucleoside reverse-transcriptase inhibitors (5.7%) over nucleoside reversetranscriptase inhibitors (0.2%). No mutations to protease inhibitors were detected. The prevalence of resistance was 22.1% based on all mutations identified through the HIVdb interpretation system. The most frequent resistance sites were E138A (9.6%), K103N (6.4%), and K101E (2.1%). The majority of detected mutations were confined to subtype A (52.6%), followed by B (19.6%). Non-Hellenic nationality was significantly associated with an increased risk of TDR (relative risk 1.32, 95% confidence interval 1.04-1.69). Conclusions: Non-B HIV infections predominate in Greece, with an increasing trend in recent years. The prevalence of TDR remains stable. Ongoing surveillance of resistance testing is needed to secure the long-term success of ART. (C) 2021 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases.